Award Abstract # 1023346
NSWP: Causal Electron Precipitation in Geospace Weather: Model Development, Validation, Event Studies

NSF Org: AGS
Division of Atmospheric and Geospace Sciences
Recipient: TRUSTEES OF DARTMOUTH COLLEGE
Initial Amendment Date: August 9, 2010
Latest Amendment Date: May 18, 2012
Award Number: 1023346
Award Instrument: Continuing Grant
Program Manager: Rachel Walker-Kulzick
AGS
 Division of Atmospheric and Geospace Sciences
GEO
 Directorate for Geosciences
Start Date: August 15, 2010
End Date: January 31, 2014 (Estimated)
Total Intended Award Amount: $307,000.00
Total Awarded Amount to Date: $307,000.00
Funds Obligated to Date: FY 2010 = $72,000.00
FY 2011 = $115,000.00

FY 2012 = $120,000.00
History of Investigator:
  • William Lotko (Principal Investigator)
    wlotko@dartmouth.edu
Recipient Sponsored Research Office: Dartmouth College
7 LEBANON ST
HANOVER
NH  US  03755-2170
(603)646-3007
Sponsor Congressional District: 02
Primary Place of Performance: Dartmouth College
7 LEBANON ST
HANOVER
NH  US  03755-2170
Primary Place of Performance
Congressional District:
02
Unique Entity Identifier (UEI): EB8ASJBCFER9
Parent UEI: T4MWFG59C6R3
NSF Program(s): MAGNETOSPHERIC PHYSICS
Primary Program Source: 01001011DB NSF RESEARCH & RELATED ACTIVIT
01001112DB NSF RESEARCH & RELATED ACTIVIT

01001213DB NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s): 9150, 9196
Program Element Code(s): 575000
Award Agency Code: 4900
Fund Agency Code: 4900
Assistance Listing Number(s): 47.050

ABSTRACT

This project is motivated by the overarching question: How does spatiotemporal variability in regional and global characteristics of electron precipitation influence the magnetosphere-ionosphere (MI) interaction? The precipitation of electrons from the magnetosphere into the ionosphere alters the electrical properties of the ionosphere. By altering the electrical conductance of the ionosphere as well as the scale height, electron precipitation plays a primary agent in regulating both the electrodynamics of magnetosphere-ionosphere coupling, but also the gravitational escape of ionospheric ions into space. For these reasons, characteristics of electron precipitation such as its flux distributions and its hemispheric power are recognized as key variables for space weather prediction. Current understanding of the effects of electron precipitation has been derived largely from index-based, non-causal empirical precipitation models and from simple first-principles models embedded in global simulations of the magnetosphere. Neither approach adequately captures the complexity or variability of electron precipitation that occurs during major space weather events such as magnetic storms. This project takes a major step in advancing the state-of-the-art by developing physically realistic electron precipitation models that can be causally regulated by state variables derived from global magnetohydrodynamic (MHD) simulations of the magnetosphere. The principal science objectives are i) to improve the fidelity of the electron precipitation fluxes predicted in numerical simulations of the geospace environment, and ii) to use the simulations to investigate the effects of electron precipitation on the MI interaction. Anticipated innovations include improvements in the specification of direct-entry, diffuse and monoenergetic precipitation and development of new models for secondary and broadband precipitation. The proposed developments will be will be tested and their accuracy calibrated in the context of a standalone version of the Lyon-Fedder-Mobarry (LFM) global simulation model as well as the coupled magnetosphere- ionosphere-thermosphere (CMIT) model, which merges the LFM model and the thermosphere-ionosphere electrodynamics general circulation model (TIEGCM). The LFM model will be used to study precipitation, field-aligned currents, convection, and joule dissipation; the TIEGCM will be used to study the impacts of precipitation on the distribution and dynamics of E- and F-region ionization and the resulting electrical conductivities.
The project integrates research and education by advancing discovery and understanding while promoting the teaching and professional development of a PhD student who will perform the bulk of the research under the mentorship of the principal investigator and his collaborators. The project will enhance the infrastructure for research and education by fostering a partnership between participating scientists at Dartmouth College and the National Center for Atmospheric Research. Project results will be disseminated in public forums, in refereed journal publications and in conference presentations. Legacies include innovative precipitation models that can be implemented in any global MHD simulation model of the magnetosphere; benefit to society by advancing our capability to forecast geospace weather; and a deeper scientific understanding of causal relationships between the physical attributes and the impacts of electron precipitation in geospace.

PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH

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Brambles, O.J., W. Lotko, B. Zhang, J.E. Ouellette, J. Lyon and M. Wiltberger "The effects of ionospheric outflow on ICME and SIR driven sawtooth events" JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS , v.118 , 2013 , p.6026 10.1002/jgra.50522
Lynch, K. A., D. Hampton, M. Mella, B. Zhang, H. Dahlgren, M. Disbrow, P. M. Kintner, M. Lessard, E. Lundberg and H. C. Stenbaek-Nielsen "(2012), Structure and dynamics of the nightside poleward boundary: Sounding rocket and ground-based observations of auroral electron precipitation in a rayed curtain" J. Geophys. Res. Space Physics , v.117 , 2012 , p.A11202 10.1029/2012JA017691.
Lynch, K. A.; Hampton, D.; Mella, M.; Zhang, Binzheng; Dahlgren, H.; Disbrow, M.; Kintner, P. M.; Lessard, M.; Lundberg, E.; Stenbaek-Nielsen, H. C. "Structure and dynamics of the nightside poleward boundary: Sounding rocket and ground-based observations of auroral electron precipitation in a rayed curtain" JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS , v.117 , 2012 , p.- 10.1029/2012JA017691
Zhang, B.; Lotko, W.; Brambles, O.; Damiano, P.; Wiltberger, M.; Lyon, J. "Magnetotail origins of auroral Alfvenic power" JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS , v.117 , 2012 , p.- 10.1029/2012JA017680
Zhang, B.; Lotko, W.; Brambles, O.; Wiltberger, M.; Wang, W.; Schmitt, P.; Lyon, J. "Enhancement of thermospheric mass density by soft electron precipitation" GEOPHYSICAL RESEARCH LETTERS , v.39 , 2012 , p.- 10.1029/2012GL053519
Zhang, B., O. Brambles, W. Lotko, W. Dunlap-Shohl, R. Smith, M. Wiltberger and J. Lyon "Predicting the location of polar cusp in the Lyon-Fedder-Mobarry global magnetosphere simulation," JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS , v.118 , 2013 , p.6327 10.1002/jgra.50565
Zhang, B., W. Lotko, O. Brambles, M. Wiltberger, W. Wang, P. Schmitt, and J. Lyon "Enhancement of thermospheric mass density by soft electron precipitation" Geophys. Res. Lett. , v.39 , 2012 , p.L20102 10.1029/2012GL053519
Zhang, B., W. Lotko, O. Brambles, P. Damiano, M. Wiltberger and J. Lyon "Magnetotail origins of auroral Alfvénic power" J. Geophys. Res. Space Physics , v.117 , 2012 , p.A09205 10.1029/2012JA017680
Zhang, B., W. Lotko, O. Brambles, S. Xi, M. Wiltberger and J. Lyon "Solar wind control of auroral Alfvénic power generated in the magnetotail" J. Geophys. Res. Space Physics , v.119 , 2014 , p.1734 10.1002/2013JA019178

PROJECT OUTCOMES REPORT

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

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